Heaney’s death in August “caught us all off guard”, said Polly Devlin, sister of Heaney’s wife Marie

Writer Polly Devlin: “He carried our aspirations, our longings for a better and more truthful life, and he carried them so lightly and with such grace, and he never let on to you that he was carrying your burden,” she said. Photograph: Heather Edwards.

The death of poet Seamus Heaney was “as if a void had opened up,” his sister-in-law, the writer Polly Devlin, said at an evening of memories, musings and music in Washington to celebrate his life.

Devlin was among friends and admirers who shared memories of Heaney’s life and work at a tribute hosted by the Irish Ambassador Anne Anderson. The small gathering included Senator Patrick Leahy, third in the presidential line of succession, and the US chief justice John Roberts.

Heaney’s death in August “caught us all off guard”, said Devlin, sister of Heaney’s wife Marie, and made people realise how much they loved him and how much he gave.

“He carried our aspirations, our longings for a better and more truthful life, and he carried them so lightly and with such grace, and he never let on to you that he was carrying your burden,” she said.

Travelling with Seamus was “miraculous,” she said – postmen, not just his postman, would greet him; taxi drivers refused to take his money. “I always tried to get a lift to the airport with him,” she joked.

Irish-American writer and professor Alice McDermott said that she has “co-taught” with Heaney for many years – so much so that her students have threatened to inscribe above her office her mantra, as a teacher of writing, the poet’s phrase: “So walk on air against your better judgment.”

Poet Paul Muldoon said he, and he suspected many others, had not accepted that Heaney was dead.

“One of the reasons why one will never take it in is that he is so present among us. I don’t think of Seamus Heaney being consigned to any past. He is part of our present and part of our future,” he said.

Anderson said the day after Heaney died, two days after she became ambassador to the US, she found a plaque next to a sorrel tree planted by the poet in the garden of the ambassador’s residence in 2000.

Joe Hassett, an Irish-American lawyer who was at the planting, read at the sorrel tree a sonnet from Heaney’s Clearances in which he pondered his mother’s death in the felling of a chestnut tree.

“There is no sugar-coating or denying the huge loss that we all feel when we think of the loss of Seamus,” said Hassett. “There is a hole there for sure, but we have our tree which I suppose figures his work, which is left eternally as a source.”